Parent Company only Condensed Financial Information - Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net Income	$ 1,258	$ 8,583	$ 7,449	$ 6,538	$ 7,215	$ 6,765	$ 7,295	$ 6,106	$ 23,828	$ 27,381	$ 16,497
Adjustments to reconcile net income to net cash provided by (used in) operations:
Amortization of restricted stock award, net of forfeitures and taxes									912	479	265
Net cash provided by (used in) operating activities									41,358	25,899	28,494
Cash flows from financing activities:
Net change in purchased funds and other short-term borrowings										(3,000)	3,000
Proceeds from issuance of common stock, net of issuance costs									1,368	938	315
Proceeds from issuance of subordinated debt, net of issuance costs									39,073
Net cash provided by (used in) financing activities									246,052	183,676	261,699
Net increase (decrease) in cash and cash equivalents									50,119	(77,989)	221,689
Cash and cash equivalents, beginning of year				266,103				344,092	266,103	344,092	122,403
Cash and cash equivalents, end of year	316,222				266,103				316,222	266,103	344,092
HCC (Parent)
Cash flows from operating activities:
Net Income									23,828	27,381	16,497
Adjustments to reconcile net income to net cash provided by (used in) operations:
Amortization of restricted stock award, net of forfeitures and taxes									912	479	265
Equity in undistributed loss/(net income) of subsidiary bank									(10,078)	(10,897)	(18,081)
Net change in other assets and liabilities									224	(109)	269
Net cash provided by (used in) operating activities									14,886	16,854	(1,050)
Cash flows from financing activities:
Net change in purchased funds and other short-term borrowings										(3,000)	3,000
Equity investment in subsidiary bank									(20,000)
Payment of cash dividends									(15,238)	(13,627)	(10,738)
Proceeds from issuance of common stock, net of issuance costs									1,368	938	315
Proceeds from issuance of subordinated debt, net of issuance costs									39,073
Net cash provided by (used in) financing activities									5,203	(15,689)	(7,423)
Net increase (decrease) in cash and cash equivalents									20,089	1,165	(8,473)
Cash and cash equivalents, beginning of year				$ 2,851				$ 1,686	2,851	1,686	10,159
Cash and cash equivalents, end of year	$ 22,940				$ 2,851				$ 22,940	$ 2,851	$ 1,686